Disk drive employing a modified rotational position optimization algorithm to account for external vibrations
AssigneeWestern Digital Technologies, Inc.
InventorsRaffi Codilian, Mark F. Vallis
Life of this patent
Estimating the term…
Abstract
A disk drive is disclosed which executes a rotational position optimization (RPO) algorithm to select a next command to execute from a command queue relative to an estimated access time. If an external vibration is detected, the RPO algorithm increases at least one of an estimated seek latency, an estimated settle latency, and an estimated rotational latency for each command in the command queue.
Claims42
A disk drive comprising:
- (a) a disk comprising a plurality of tracks;
- (b) a head actuated radially over the disk;
- (c) a command queue for storing a plurality of commands pending execution;
- and
- (d) a disk controller for executing a rotational position optimization (RPO) algorithm to select a next command to execute from the command queue relative to an estimated access time comprising:
- an estimated seek latency required to move the head radially over the disk to a target track comprising the next command;
- an estimated settle latency required for the head to settle over the target track, wherein the settle latency occurs after the seek latency;
- and
- an estimated rotational latency required for the disk to rotate until the head reaches the next command, wherein the rotational latency occurs after the settle latency,
- wherein the RPO algorithm increases at least one of the estimated seek latency, the estimated settle latency, and the estimated rotational latency for each command in the command queue if an external vibration is detected.
A method of operating a disk drive, the disk drive comprising a disk having a plurality of tracks, a head actuated radially over the disk, and a command queue for storing a plurality of commands pending execution, the method comprising the steps of:
- (a) executing a rotational position optimization (RPO) algorithm to select a next command to execute from the command queue relative to an estimated access time comprising:
- an estimated seek latency required to move the head radially over the disk to a target track comprising the next command;
- an estimated settle latency required for the head to settle over the target track, wherein the settle latency occurs after the seek latency;
- and
- an estimated rotational latency required for the disk to rotate until the head reaches the next command, wherein the rotational latency occurs after the settle latency,
- (b) detecting an external vibration;
- and
- (c) increasing at least one of the estimated seek latency, the estimated settle latency, and the estimated rotational latency for each command in the command queue in response to the detected external vibration.
Dependencies are inferred from the claim text.